package com.itheima.reggie.controller;

import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;


/**
* @Description: 文件的上传和下载
        * @Param:
        * @return:
        * @Author: Lei
        * @Date:
 */

@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {


    @Value("${reggie.path}")
    private String basePath;


    /**
    * @Description: 文件上传
            * @Param: 
            * @return: 
            * @Author: Lei
            * @Date: 
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file){
        /**当前file是一个临时文件，需要转存到指定位置，否则本次请求完成后临时文件会删除*/
        log.info(file.toString());

        /**原始文件名*/
        String originalFilename = file.getOriginalFilename();
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));

        /**使用UUID重新生成文件名，防止文件重复造成文件覆盖*/
        String fileName = UUID.randomUUID().toString()+suffix;

        /**创建一个目录*/
        File dir=new File(basePath);
        /**判断当前目录是否存在*/
        if(!dir.exists()){
            /**目录不存在，需要创建*/
            dir.mkdirs();
        }



        try {
            /**将临时文件转存到指定位置*/
            file.transferTo(new File(basePath+fileName));
        }catch (IOException e){
            e.printStackTrace();
        }

        return R.success(fileName);
    }


    /**
    * @Description: 文件下载
            * @Param: 
            * @return: 
            * @Author: Lei
            * @Date: 
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response){

        try {
            /**输入流，通过输入流读取文件内容*/
            FileInputStream fileInputStream=new FileInputStream(new File(basePath+name));
            /**输出流，通过输出流将文件写回浏览器，在浏览器展示图片*/
            ServletOutputStream outputStream = response.getOutputStream();
            response.setContentType("image/jpeg");

            int len=0;
            byte[] bytes=new byte[1024];
            while ((len=fileInputStream.read(bytes))!=-1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }

            /**关闭资源*/
            outputStream.close();
            fileInputStream.close();
        } catch (Exception e) {
            throw new RuntimeException(e);
        }




    }
}
